Resistance controlling device



'Dec. 1, 1931. 1.. FLANDRIN ET'AL RESISTANCE CONTROLLING DEVICE Filed July 18, 1930 nvenforsr- W/ .4 f mwm 5 a m N I? Patented Dec. 1, 1931 "UNITEDISTQATTES PATENT" OFFECE PARIS, FRANCE RESISTANCE CONTROLLING DEVICE ucationmea iul s, 1e30, seriaIN j4sa9s0, and in France July 20, 1929.

Our invention has forits'object' a controlling device which serves to insertan addi tional resistance in a circuit or to removeit therefrom according to the value ofthe resistance infthe circuititself. 1

i This device may more particularly be used "for limiting the current in a shunt whichit respectively.

autom atically puts back into its original state when the rate of flow s again normal,

after a short-circuit or a rise of intensity above the maximum intensity that has been provided for. p p V Our invention conslsts 1n mounting 1n se- "riesin the circuit twoelectro-magnets and the additional-resistance and in shunting this resistance, together with theelectro-magnet which is adjacent to it, by means of a connection comprising two contacts in series, each of these contacts being operated through the movable core of each of the electro-magnets The electro-magnet which is not shunted is so chosen as to draw its movable coreandthus open 'thecorrespondin'g contact when the current rises above a certain value, as a result of an exaggerated demand ;or of a short circuit. This breaks the shunt so that the other electro-magnet and the additionalresistance are inserted in-themain circuit. It results therefrom first thatthe second electromagnet draws its core, therebyopening the corresponding contact, and alsothat, the current decreasing in"thejcircuit.- the first elec- 'tro-magnet'lets its contact close again. The 1 second electro-magnet isso chosen as to release its core onlywhfen the resistancein the circuit falls back to a value .that corresponds to'the makimum current'fthat must pass in the circuit, or to anyjother value below that one. i

When'this condition is fulfilled, the'closing of the above mentioned contact produces the makeof the shunt. which had been prepared bv the closing of the contact of the first eleotro-magnet, which immediately follows the-opening of the contact Ofthe second electro-magnet.

Our invention will bedescribed with refierence to the appended drawings in which: Figs. Ito4 are diagrammatic Views of our of our invention.

The additional resistance 6 is-inserted in se ries'with the electro-magnet c and d in one of the conductorsof the circuit a which is to be controlled. Thewhole of resistance 12 They are so disposed as to be opened whenever the corresponding core is drawn by its magnet.

This device is placed for instance on a service-lead. Normally none of the cores is drawn by its electro-magnet. a

The current, flowing through electro-mag-. net d, is sent to the utilization apparatus" through shunt e (Fig.1). If the resistance of the circuit to be controlled decreases, either because too many utilization apparatus 2 areconnected to this circuit, or on account of,

a short-circuit, the current thorugh the electro-magnet cl increases. As this electro-magnet isso chosen as to become capable, under thesecondtions, of drawing its core, the contact g is opened (Fig. 2). v 'The shunt (2 being then broken, the current i passes through resistance band electro-magnet 0, which is thus energized. "The electromagnet 0 1S. so chosen as to be capable,under LUDOVIC rnennmn, or NEUILLY sun SEINE, Am) GEORGES CLEMENT LEVY, or r I and electro-magnet 0 is shunted by a conne'c-. tion e' comprising two contacts; 7 g inseries." 7 Contacts 7 and g are operated by the movable cores of-electro-magnets c and d respectively.

these circumstances, of drawing its core; v

which then opens contactsf (Fig. 3) 3 But, on account'o'f the insertion ofresistance I) in the oircuitgthe intensity of the current that passes through electro-magnet d hesfallen down'to the normal value or. below it. It results therefrom that this electro-mag'net can no longer keep its core in a raised positionand must letcontact g close again. (Fig. 4). j

The device remains in this positionuntil the short-circuit is'eliminated or the demand reduced to a normal value. When this is done the intensity decreases in the circuit, so that electro-magnet'c lets contact 7 close again. The device is then again in its orig-. inal position (Fig. 1) and is ready to operate once more as above described, without it being necessary to act directly upon it.

Our device could also be used for instance for automatically inserting a resistance in the circuit of a motor in case of overload.

Likewise, being given two motors connected inscries a dovice accordingto our invention may be inserted in their feed circuit, the additional resistance being chosen equal to the resistance of one of the motors. If a short-circuit occurs in one of said motors,

the additional resistance will automatically be substituted for this motor, as far as the question of resistance in the circuit is concerned, which will protect the other motor, thus enablingrthelatter to keep on. running as an emergency motor.

A device of this-kindcan be used-in connection with arc-lamps or other utilization apparatusarranged' in series, in order to insert the additional resistance in case of short-circuit in one of them.

As another example of application, our device may very advantageously beused for inserting a. resi stance in the neutral wire of a= three-wire distribution. when. this wire tends to become overloadedon. account of: an inequalityin the currents through the'two bridges Contacts f and 7 shall preferably be of the type described incur French patent Ser. No. 662,267,.filedFebruary 4, 1928, formercury circuit-breakers. It is particularly advantageous to use the V-shaped circuit breakers described in said patent.

This embodiment h as'been showniin Figs. 5 and 6. The-circuit breakers f and g are each mounted on a disk f g respectively, pivotally mounted on an axis passing througlrits center. Disks f and g are provided with counterwaight-s f g which are preferably adjustable.

' Alt points 7 a' of the periphery of these disks are fixed flexible wires which are partially wound round the disks and are fastened to the cores 0 d" of the electro-magnets 0 (Z respectively.

Oneof theelectrodes of each circuit-breakor is connected by means of flexible wires to the shunt 6 while the other electrodes are connected together by similar wires. In Fig. 5, the circuit-breakers are shown as making the shunt, in Fig. 6 as breaking it.

A small lamp at low voltage h is inserted between two points of the additional resistance b, said lamp being lighted when the resistance is in the circuit.

The whole of the device is covered by a casing 71 (Fig. 6) provided with a large glass window 7', through which the circuit-breakers can be seen, and with a peep-hole in behind which is: located lamp 72 Of course our invention is not" limited to the use of mercury circuit-breakers of any kind, as any other equivalent means could be used.

While we have disclosed what we believe to be the preferred form of our device, we do not wish to be limited thereto as there might be changes made in the construction dispositionand shape of the parts withoutxdeparting from the spirit of our invention as comprehended within the scope of the appended claims. For instance, for relatively small currents, the electro-magnet 0 could be given a sutlicient resistance for making resistance b unnecessary. Furthermore, the applications of our invention-are not limited to the examples that have been indicated.

Whatwe claim is:

1; A: device for insertingina circuit oriemoving therefrom an additional resistance, accordingto the-value ofthe resistance in the circuit, which comprises two electrmmagnets and a resistance insertedin series in the'order nainediin'the circuit to be controlled, a shunt extending around the resistance and the electro-magnet adjacent thereto, two switches in series in saidshunt, and means,,actuatedby.

the two electro-magnetsrespectively, for op erating said switches.

2. Device for inserting in a circuit or removing therefroman additional resistance,

according to the-value of the resistance in.

the circuit, whichcomprises two electrofmagnets-and a resistance inserted in-ser'ies in the order named in thecircuit tobe controlled, movable coresin-said electro-magnets, a shunt extendingaround the resistance andthe electro-ma gnet adjacent thereto andt'wo-switches inseries in said shunt adapted tobe operated by themovablecones of the electro-magnets.

' 3. Device for inserting in a circuit or'removing therefrom an additional resistance,

according to-the value of the resistance in the circuit, which comprises an emergency resistance, and electro-Inagnet in series with said resistance, a-movable core adapted to be actuated by said' electno-magnet when the.

current flowing through it exceeds a certain maximum, another electro-magnet in series with the first one. a movable core'adapted to be actuated by this electro-magnet when the current flowing through it exceeds acertain' value higher than the above mentioned maximum, the resistance. and the two magnets being inserted. in series in. the order named in the circuit to be controlled, a shunt extending around the, resistance and the electromagnet adjacent thereto, and two circuitbreakers, inserted in series in said shunt, adapted to be operated by the movable cores of the electro-magnets respectively.

4. Device for inserting in a circuit or re moving therefrom an additional resistance, according to the value of the resistance in the circuit, which comprises an emergency resistance, an electro-magnet in series with said resistance, a movable core adapted to. be actuated by said electro-magnet whenthe current flowing through it exceeds a certain maximum, another electro-magnet, in series with'the first one, a movable core adapted to I 5 be actuated by this electro-magnet when the 1 current flowing through it exceeds a certain value higher than the above mentioned maximum, the resistance and the two magnets being inserted in series in the order named w in the circuit to be controlled, a shunt extending around the resistance and the electromagnet adjacent thereto and two rotatable mercury circuit-breakers inserted in series in said shunt, adapted to be rotated by the movi5 able cores of the electro-magnets respectively, In testimony whereof we have signed our names tothis specification. LUDOVIC FLANDRIN. GEORGES CLEMENT LEVY. 

